Burner control valve



R E NEWELL, JR

BURNER CONTROL VALVE Filed Aug 5, 1949 III I 1 March 24, 1953 INVENTOR.203527 E. NEWELL,JR. BYZ Z 21/ w l a HTTOPNE Patented Mar. 24, 1953UNITED STATES PATENT OFFICE BURNER CONTROL VALVE Robert E. Newell, Jr.,Irwin, Pa.

Application August 5, 1949, Serial No. 108,683

6 Claims.

My invention relates to thermally-actuated control devices that areespecially suitable for use with the-safety pilots of gas burners.

One object of the invention is to provide a flame-responsive assemblyfor such safety pilots, that will be cheaper to manufacture; that willbe stable at a given setting, and which may be operated by a small pilotflame having a single jet or wide flame adapted to contact the thermaldevice and to ignite the main burner, simultaneously.

A further object is to provide in said thermal device or assembly anexternal thermal element near to the main heating burner and contactedby the pilot flame, with means for communicating its movement to aninternal operating lever, extending to a point within a valve chamber,remote from the burner, without the use of sliding parts, gland pins,packing, etc.

Although my thermal device may be used to operate various types ofvalved mechanism, either gradual or snap-acting, I shall, for thepurpose of this application, describe a manually reset valve of thestyle shown in Robert E. Newell application Serial No. 639,965, filedJanuary 9, 1946 (Patent 2,499,253).

In the accompanying drawing: Figure l is a sectional view of my controldevice, showing its relationship to a gas valve and a burner; Fig. 2 isa face view of the bracket member at the forward end of the structure ofFig. 1; Fig. 3 is valve body or housing 7 that contains a valve 8 forcontrolling flow of gas through the valve body to a main burner 9, itbeing understood that a suitable piping connection will be pro-' videdbetween the valve body and the burner. The valve 8 is carried by a valvestem It and is yieldably held on its seat II by a compression spring l2.s 4

A burner tip I 3 which may suitably be of stainless steel has a hole orport M of generally circular form and is also provided with a relativelynarrow slot I5 that extends back-wardly from the port l4. pipe itsupported upon the valve body and communicating with a port I"! throughwhich gas may be supplied from any desired source to the pilotburner-tip l3.

A supporting tube [8 is carried by the valve body 1 and it may suitablybe of cadmium-plated The tip I3 is carried by a" carbon steel. A bracket19 is welded to the forward end of the tube l8. This bracket is of ametal having low co-eflicient of expansion, such as a nickel steelalloy. An operating lever 20 which can suitably be of chrome-nickelalloy extends through and has drive fit with the bracket 19, to preventleakage of gas from the tube l8. At its rear end, this lever has a stem2| which, when the apparatus is in a normal state of operation, hasabutting engagement with the forward end of the valve stem II], to holdthe valve 8 in its open position, for supply of gas to the main burner9. The lever and its extension thus function as a latch.

A thermal strip or plate 22 is welded at its upper edge to the bracket[9 and near its lower edge is welded to the lever 20. Thiselement 22 isof metal such as a chrome-nickel alloy, has a high co-eihcient ofexpansion relative to the metal of bracket I9.

So long as a supply of gas is maintained to the pilot tip, the lever 20will be held in the position shown in Fig. 1 and the gas valve 8 therebyheld open. If the pilot flame becomes extinguished for any reason, theconsequent cooling of thermal element 22 will result in tilting of thelever 20 to its dotted line position, to'release the valve stem IS andpermit the valve to be closed by its spring l2. Upon relighting thepilot tip the flame through the slot 15 will reheat the thermal strip 22and restore the lever to its valve-holding position, so that when thevalve 8 is'pulled open its stem l9 and the lever stem 2| willagainbecome interengaged.

Should the burner tip become clogged, the slot IE will become cloggedbefore the port I4 becomes clogged. This will result in cooling of thestrip 22 and consequent closing of the valve 8 while the flame orignition jet at I4 is still burning. A similar safety result will occurin case of an extreme drop in gas pressure, since the sheet of flamethat issues from the narrow slot l5 will be extinguished before failureof the jet at the larger port It.

In some types of pilot flame controls there has been a tendency forthe'pilot flame to be cut off unnecessarily, owing to drafts,over-firing of the heater, defective or over baffled flues, etc.

This objection is overcome by my present invention, owing to the factthat a considerable period of time is required for the thermal strip tobecome cooled to a point at which it will operate the control lever 20,and to the fact that the thermal heating and the ignition flames arecompact and located close to the main burner where,

in the average combustion chamber, fresh secondary air keeps the pilotflame supplied with oxygen.

The present thermal device is cheaper to manufacture due to the smalleramount of expensive alloys required. Because of the high amplificationof movement of the operating lever 3, a very small thermal strip isrequired (being in actual practice only about long), in order to obtaina movement of .040 to .060 at the free end of the operating lever.

Due to the small size and lightness of the thermal element, and the factthat it is not secured to the large mass of the main burner, nocompensation is needed to reduce the operating time.

It will be understood that the-thermal device can be used also tooperate electrical switches, or other control devices.

I claim as my invention:

1. A thermally-operated control device comprising a housing, a gas valvethat is mounted in the housing and has a stem that is movable to openand close the valve, a tube connected to the housing and open at itsrear end, for access to the valve stem, a bracket rigidly secured to theforward end of the tube, a latch lever supported intermediate its endsby the bracket and extending through the bracket and disposed within thetube into position to eiTec't engagement with the valve stem andreleasably hold the valve off the valve seat, a thermal strip having ahigh coefiicient of expansion relative to the bracket secured at one endto the bracket and secured near its other end to the forward end of thelatch lever and extending transversely thereof, and a pilot flame tippositioned to ignite a gas burner and to heat the thermal strip, wherebyheating and cooling or" the strip will efiect rocking of the latch leveron the bracket, to move the inner end of the lever into and out oflatching position relative to the valve stem.

2. A thermally-operated device as recited in the preceding claim,wherein the tip has a jet opening for igniting the burner and a slot forproducing a thin, wide flame for heating the thermal strip.

3. A thermally-operated device comprising a tubular support adapted forconnection at its rear end to apparatus to be controlled, and open atits rear end, a bracket extending'across the forward end of the supportand having a wall portion deflected into the support for a substantialdistance, an operating lever extending through and pivoted on the saidwall portion and extending through the tubular support, and athermally-responsive element secured to an edge portion of the bracketand to the adjacent end of the lever, whereby upon heating of theelement by a flame the lever will be rocked relative to the tubularsupport.

- 4. A thermally-operated device comprising a tubular support adaptedfor connection at its rear end to apparatus to be controlled, and open 4at its rear end, a bracket extending across the forward end of thesupport and having a wall portion deflected into the support for asubstantial distance, an operating lever extending through and pivotedon the said wall portion and extending through the tubular support, athermally-responsive element secured to an edge portion of the bracketand to the adjacent end of the lever, whereby upon heating of theelement by a fiarne the lever will be rocked relative to the tubularsupport, and a gas pilot burner carried by the said bracket, in positionto heat the thermal element, the burner having an opening which directsasheet of flame against the said element and a jet flame in a directionaway therefrom.

5. A thermally-operated device comprising a gas valve chamber, a gasvalve therein, for controlling flow of gas through the chamber, a springnormally urging the valve to its closed position, a stem on the valveand having one of its ends protruding through a wall of the chamber, atube having one end tightly connected to the said wall, incircumferential relationship to the protruding end of the stem, abracket plate extending across the forward end of the tube and snuglyconnected thereto, the plate being provided with a central perforation,a latch lever arranged in generally end-to-end relation with theprojecting extremity of the valve stem and extending through saidperforation, with a snug fit, and a thermal strip rigidly secured at oneend to the forward end of the tube and extending transversely or thelever and rigidly secured to the extremity of the lever, adjacent to theother end of the strip, whereby heating and cooling of the strip wiilrock the lever on the plate.

6. A thermally-operated device comprising a tubular support adapted forconnection at its rear end to apparatus to be controlled, and open atits rear end, a bracket secured across the forward end of the supportand having a hole therethrough, the bracket serving as an end wall forthe tubular support, an operating lever extending through the hole andpivoted on the bracket,

- and extending lengthwise through the tubular support, and athermally-responsive element rigidly secured to the bracket andextending from one edge thereof and rigidly secured to the adjacent endof the lever, whereby upon heating of the thermally-responsive elementby a flame, the lever will be rocked relative to the tubular support.

ROBERT 'E. NEWELL, JR.

REFERENCES CITED The following references are of, record in the file ofthis patent:

UNITED STATES PATENTS 60 Number Name Date 1,966,735 Sackett July 17,1934 1,980,129 Walker et a1. l Nov. 6, 1934 2,015,318 Schnepp et alSept. 24, 1935 2,068,429 Mustee Jan. 19, 1937

